Breaking in question.

[Zachary]

Okay well today I was in the process of breaking in my brand new g-27cx supertigre and after one tank off the ground and the other two on the street on 1/4 throttle I noticed it was going through gas like crazy. I checked the temp and it was 196.7F and so it wasn't rich enough to be drinking the nitro like that. then i noticed after i filled it up i had a huge crack down the back side of my tank and it was leaking like a son of a bitch. should i just continue with the break in or start over?

Also are the supertigre engine suppose to run hotter then most engines or cooler. One guy at my lhs says hotter and the other at the same lhs says cooler witch one is right? I was told to get the temp to like 250 for break in and the other said 180ish. witch is right?

 

[HeartBreak]

Right around 200-210 for breakin.

And I'd recommend replacing that tank before continuing. No damage should be caused, since the temps were in the correct ranges.

 

[Rolex]

Absolutely, you need to replace the tank.
The fuel system is a closed loop, depending on pressure from the exhaust to push fuel out of the tank and into the carb.
Air leaks anywhere in that loop cause major nightmares, and will likely cause your engine to overheat due to a lean condition.

 

[MadRussian]

Absolutely, you need to replace the tank.
The fuel system is a closed loop, depending on pressure from the exhaust to push fuel out of the tank and into the carb.
Air leaks anywhere in that loop cause major nightmares, and will likely cause your engine to overheat due to a lean condition.

Seconded. The fuel system MUST not have ANY leaks!

 

[olds97_lss]

Unless you a really tight engine, it is typically difficult to get the temps up to 210F within your first tank without running almost too lean. I normally hit 200F'ish by the time I reach the end of tank two.

I never let my engine sit and idle during break-in though. I go easy on the gas to about 1/2 throttle and easy off the gas for the first few tanks. After tanks 3-4, I do the same but go to about 3/4 throttle. Not quick jabs, just roll up to 3/4, then roll back down. After tank 5 or so, I roll up to WOT and back down. Normally I start leaning them out a bit at a time throughout to get the temps up to and stay around 210F-240F.

 

[Zachary]

Okay well i just put in a new tank today. Will have to start it tomorrow and see what happens.

Another question is,

The spring that holds the little pin in the crankshaft fell apart. The engine started no problem and then all the sudden, when i put the starter on the back there was no grip at all. I toke off the backplate and pulled the little pin and then the spring, as i was pulling the spring though it broke in three parts. What would cause that?

 

[HeartBreak]

Most likely a defective spring. I've never seen one break in three pieces like that.

 

[MadRussian]

Unless you a really tight engine, it is typically difficult to get the temps up to 210F within your first tank without running almost too lean. I normally hit 200F'ish by the time I reach the end of tank two.

I never let my engine sit and idle during break-in though. I go easy on the gas to about 1/2 throttle and easy off the gas for the first few tanks. After tanks 3-4, I do the same but go to about 3/4 throttle. Not quick jabs, just roll up to 3/4, then roll back down. After tank 5 or so, I roll up to WOT and back down. Normally I start leaning them out a bit at a time throughout to get the temps up to and stay around 210F-240F.

Dude. All you have to do is wrap the head in tin foil. :yes:

 

[ohmygahitscoby]

Dude. All you have to do is wrap the head in tin foil. :yes:

But you want the engine to create 200-210 degrees, not give the engine 200-210 degrees.

 

[Zachary]

Another thing in this engine is that it doesn't like to fire right off the bat. I have a roto starter backplate thats on the back and i have it just hocked up to a drill. I will put a brand new plug on, freshly charger glow warmer and it still takes forever to start. Is the drill just not spinning as fast a roto or whats the problem? Or is that just normal with new engines? I have never had this much of a problem with any engine i have ever had so this is bugging the poop out of me. I'm half tempted to just put the damn protech back in the thing.

 

[Rolex]

More than likely your drill is not nearly as fast as the roto start.

 

[Zachary]

Okay well luckly i will have one on saturday.

 

[MadRussian]

But you want the engine to create 200-210 degrees, not give the engine 200-210 degrees.

You may want to rethink that. Every single racer I know of does that to use the heat cycle method. If you dont you will be stressing th eengine too hard during break in to reach those temps, especially when its cold outside.

 

[neobart]

To clarify what Madrussian is saying, wrapping the head while doing break-in allows the engine to reach temps around 200f without running it too lean.